The Mason Hale Award of the International Association for Lichenology (IAL) is for outstanding work resulting from doctoral dissertations or similar studies. The award was introduced in 1992, and past recipients are among the most productive and innovative lichenologists of today. This demonstrates that a high quality dissertation can predict future success in the field, and the award for 2010 is made to Suzanne Joneson.
Suzanne Joneson’s thesis, The Molecular Biology of Lichen Symbiosis and Development, was accepted by Duke University for the degree of PhD in 2009. Her thesis represents a series of innovative studies exploring the operation of the lichen symbiosis at the functional level, using the latest available molecular approaches as well as culture experiments.
She explored the earliest steps in the initiation of a lichen thallus by studying the response of the lichen-forming fungus Cladonia grayii to contact with it’s usual Asterochloris algal partner, other cellular and also filamentous algae, a moss protonema, and inert glass beads. In addition she examined the effect of growing the Asterochloris with the fungus but separated by a nitrocellulose filter which only allowed molecular interactions. This series of experiments established that the change in hyphal branching seen in the first stages of lichenization was not just a thigmotropic response, i.e. one to contact, but something much more specialized.
To explore what this “something” could be, Suzanne turned to comparative genomics, using suppression-subtractive-hybridization (SSH) to ascertain differential gene expression – comparing genes that were operational in the pre-contact and post-contact stages of lichenization in the experiments with those expressed when the partners were growing in isolated culture. She then constructed chromosomal DNA libraries for potentially involved genes, sequencing around 500-1000 clones from each and checking for possible roles by comparison with genes of reported function.
Suzanne then went on to select genes that seemed most promising because of reported involvement in fungal pathogenicity and endeavoured to verify which were involved using quantitative PCR (qPCR) and measured their levels in lichenized and non-lichenized states of the fungal partner. Especially exciting was that, not yet satisfied and wanting to link expression to function, she engineered one of the genes, a lipase, into yeast to enable her to conduct experiments as to its role. This achievement, successfully inserting a gene from a lichen-forming fungus into a yeast, opens up new vistas towards our understanding of all aspects of the lichen symbiosis at the molecular level.
Comments made to the Award Committee during the assessment process included: “Groundbreaking work that has provided the most definitive characterization to date of the genetic basis of the lichen symbiosis”, “Suzanne’s thesis is a turning point and landmark, which is associated with the initiation of a completely new line of research”, and “She is the type of high-flyer which is urgently needed in our discipline”. Suzanne has, and continues to, operate in the innovative way Mason Hale experimented with upcoming new methodologies from the mid-1950s into the early 1970s in particular, and is consequently a most worthy recipient of this award.
– David L Hawksworth, Madrid